As the anode voltages of color cathode ray tubes have risen (currently about 30KV) and the electron guns have gotten smaller, severe problems of internal arcing during normal tube operation have occurred. In order to avoid these problems tube manufacturers have supplied an arc limiting resistor between the final anode of the electron gun and the internal conductive layer.
This arc limiting resistor can take the form of a high resistance electrical coating in the neck area of the tube, such as is shown in U.S. Pat. Nos. 4,101,803 and 3,961,221. This technique, however, necessitates the use of another resistor employed in series with the popularly used antenna getter to avoid shorting out the arc limiting resistor. This corrective procedure is also discussed in the above-cited patents.
Alternate methods of supplying an arc limiting resistor are shown in U.S. Pat. No. 3,882,348 and, U.S. Ser. No. 30,415 filed of even date herewith.
In these embodiments a separate manufactured resistor element is attached to the final anode and the internal conductive layer, adding to the cost of the gun.